1. Field of the Invention
The present invention relates to an apparatus for observing an assembled state of components, such as when a semiconductor chip is mounted on a substrate, and to a method of observing the assembled state of components using such apparatus. In more detail, the invention relates to an apparatus for observing an assembled state of components that can observe conditions such as whether voids (bubbles) have been produced in resin when resin is provided between a substrate and a workpiece and heat and pressure are applied to join the workpiece to the substrate via the resin, and to a method of observing an assembled state of components using such apparatus.
2. Related Art
One method of flip-chip bonding a semiconductor chip to a substrate supplies resin to a chip mounting position on the substrate and bonds the semiconductor chip to the substrate by applying heat and pressure to the semiconductor chip. With this bonding method, when the semiconductor chip has been mounted on the substrate, voids (bubbles) are sometimes produced in the resin (i.e., “underfill resin”) that fills the space between the substrate and the semiconductor chip. Products where voids are present in the underfill resin suffer from the problems of less reliable bonding between the substrate and the semiconductor chip at positions where voids are formed and of migration occurring at the voids, resulting in wires becoming short-circuited. Accordingly, there is demand for a method of bonding a substrate and a semiconductor chip that does not leave voids in the underfill resin.
To prevent voids from occurring, it is necessary to identify what is causing the voids. However, to identify what causes voids to be produced in resin, current methods involve only dismantling products, checking for the presence of voids, and then trying to work out how and why the voids occur.
On the other hand, in the field of resin sealing apparatuses used for semiconductor devices, a method of controlling a resin sealing apparatus used for semiconductor devices has been proposed (see Patent Document 1, for example). This method observes the behavior of resin when filling a cavity and feeds back the results of such observations so that improved control can be carried out over the filling apparatus used to fill the cavity with resin.
Patent Document 1
Japanese Laid-Open Patent Publication No. 2000-200796